1. Field of the Invention
The present invention relates to sidewalk and methods for joining composite sidewall panels and, more particularly, to a sidewall and method for joining composite sidewall panels of a cargo container by adhesive bonding.
2. Description of the Related Art
The bonding of pre-painted, substantially identical sidewall panels 1121 and 1122, especially of a sidewall (or a front wall, or a door) 110 of a cargo container, such as van-style cargo truck body, trailer or the like, involves adhesive bonding the pre-painted sidewall panels 1121 and 1122. Specifically, each of the sidewall panels 1121 and 1122 comprises a first skin 114, a second skin 116 and a core board member 118 sandwiched between the first and second skins 114, 116. The first skin 114 of each of the sidewall panels 1121 and 1122 includes an overlapping portion 115 extending laterally away from an edge of the core board member 118. Exterior surfaces of the first and second skins 114, 116 of each of the sidewall panels 1121 and 1122, including both surfaces of the overlapping portion 115 of the first skin 114, are pre-painted, i.e., covered with paint coatings 128, 130 and 132, as shown in FIGS. 1A and 1B.
The adhesive bonding of the sidewall panels 1121 and 1122 is done with metal bonding type of adhesive 136 that adhesive bonds the overlapping portion 115 of the first skin 114 of the sidewall panel 1121 to the second skin 116 of the sidewall panels 1122. The strength of this adhesive bond is determined by the strength of the adhesive 136 and by the strength of the bond to the pre-painted surface that the adhesive 136 is applied to. The painted surfaces of the first and second skins 114, 116 of the sidewall panels 1121 and 1122 have a surface energy value that can vary when different paint colors are requested and/or when the type of paint coating changes. Because of this difference in surface energy created between colors or paint coatings, the strength and the mode of failure performance of the adhesive bond (joint) are affected.
Thus, conventional methods for adhesive bonding composite sidewall panels are susceptible to improvements.